Missed Abortion -
Introduction

An abortion is a pregnancy that ends
before the baby can survive outside the womb because
it has not yet reached viability.

An abortion
may be early - during the first 14 weeks of
pregnancy, or late. The vast majority are
early - only about 1% of abortions are
late.

The definition of a abortion is a spontaneous loss of a pregnancy before
24 weeks: in the UK we calculate the duration of a pregnancy from the first
day of the last period (LMP). A abortion - the medical term for an early
pregnancy loss is abortion - tends to start with bleeding, and pain may then
develop.

A missed abortion is characterised by there being no reasons to have suspected
that the pregnancy is not going to continue but the embryo has
died.

An inevitable abortion means that
the pregnancy cannot be salvaged. It may be incomplete, with pregnancy
products still in the cavity of the womb or complete with nothing remaining.

The combination of modern pregnancy tests and ultrasound
will usually determine the situation quite quickly. Pregnancy
tests these days should become positive within ten days of
conception (i.e. even before the first missed period).

Ultrasound begins to show a pregnancy within the uterus by
five or six weeks (a week or two after the first missed
period). On occasion, it may be too early to diagnose the
situation accurately and tests may need to be repeated to
see what changes occur.

Types of
abortion

Table 12.1 indicates the various terms most frequently associated with
abortion.

Type of abortion

Description

Spontaneous Abortion

This is when the abortion occurs naturally as opposed to being induced.

Induced Abortion

The pregnancy is terminated
artificially.

Threatened Abortion

There is bleeding and sometimes pelvic
pain but the cervix is closed and ultrasound indicates an
ongoing pregnancy within the uterus.

Inevitable Abortion

The pregnancy is not continuing.

Complete Abortion

An inevitable abortion and the uterus
has completely emptied itself.

Incomplete Abortion

An inevitable abortion with products of
the pregnancy still present in the uterus.

Missed Abortion

There are no reasons to have suspected
that the pregnancy is not going to continue but the embryo has
died.

Septic Abortion

The abortion has been complicated by
infection.

Recurrent or habitual Abortion

Most authorities recommend that these
terms should be used only for three or more consecutive
abortions although there is a tendency towards two.

Early Abortion

Abortion in the first few weeks of
the pregnancy.

Late Abortion

Abortion after the first few weeks.

First trimester Abortion

Abortion before thirteen weeks of
pregnancy.

Second trimester Abortion

Abortion after thirteen weeks and
before twenty four weeks.

Abortion
symptoms

The first abortion symptom is vaginal
bleeding, which can range from spotting to being
heavier than a period.

A little spotting may be
an early sign of abortion although
fortunately this may amount to no more than a
threatened abortion and the pregnancy
continues.

The second abortion symptom is
pelvic pain.

The third abortion symptom is
cessation of pregnancy symptoms including breast
tenderness, morning sickness and having to pass
urine more frequently than usual.

Sometimes there may be no sign or symptom to
suggest abortion and pregnancy symptoms
continue, and the abortion is only discovered
in a routine scan. This is a missed abortion.

A threatened abortion occurs when there is
vaginal bleeding but ultrasound confirms a
viable pregnancy.

Cause of
Abortion

Often the cause of a abortion
remains unknown. The most common cause for
abortion is a blighted ovum - the afterbirth
type tissues develop but there is no baby.

Another common cause is a genetic defect and
nature decides not to allow the pregnancy to
continue.

Smoking and obesity may contribute to
abortion but do not cause abortion by
themselves.

Similarly, stress may play a role
in pregnancy loss, but it hasn't been shown to
cause abortion on its own.

Prevalence Of
Abortion

It is thought that between 10 and 20% of pregnancies miscarry. Most
abortions occur in the early weeks of pregnancy. Ultrasound screening for
fetal anomaly has shown the incidence of non-viable pregnancy at 10-13 weeks
to be 2.8%

Blighted Ovum

Normally the fertilised egg divides and part becomes the embryo (future
baby) and part becomes the afterbirth type tissue (trophoblast) and the
membranes that form a fluid filled bag around the baby. When there is a
blighted ovum, the afterbirth tissues develop alone without the development
of the baby. Blighted ovum hasalso been referred to as an 'anembryonic
pregnancy'. Nearly half of early abortions are associated with a blighted
ovum. It is likely that abnormal chromosomes are more prevalent.

Pregnancy
Tests

Pregnancy tests are designed to determine the presence of the pregnancy
hormone HCG. Until twenty years ago, pregnancy tests were biological,
relying on the affects of the hormone on animals. There could be a
cross-reaction with other hormones, notably LH. Many women reaching the
menopause could have a false alarm as LH levels rise at the menopause and
when they missed their periods their pregnancy tests could be falsely
positive. Modern pregnancy tests are monoclonal they react only with the
specific hormone they are designed to detect. In the early weeks of
pregnancy, the HCG level doubles every two days. Whereas the old pregnancy
tests would become positive with a concentration of 3,000 IU (about two
weeks after the missed period) the monoclonal tests show a positive result
at between 25 and 50 IU and these levels are reached before a period is
missed.

The accuracy of modern pregnancy tests are not only useful
in the early detection of pregnancy but also in assisting in
the management of early pregnancy problems such as
missed abortion or possible ectopic pregnancy.

A lady presented with vaginal bleeding and left sided
pelvic pain. Her pregnancy test was positive and ultrasound
did not show any sign of a pregnancy either within or
outside the uterus (ectopic pregnancy). Her beta HCG level
was 365 units suggesting a very early pregnancy at most. Two
days later the level had fallen to 180 units which indicated
that the pregnancy was not continuing. We could not say for
certain whether this had been an intra-uterine pregnancy
that miscarried or a possible ectopic pregnancy that was
being resolved by nature but no operative intervention was
required.

Treatment of Abortion

The options for managing abortion are outlined in
Figure 12.1. If abortion is threatened, you will usually be advised
to rest for a few days and a repeat scan will confirm whether the pregnancy
is continuing. There have been several important developments in the
management of abortion in recent years. The combination of highly
sensitive pregnancy tests and ultrasound will usually assist in providing an
accurate diagnosis. Many hospitals now have an early pregnancy assessment
unit that specialise in these problems. This should allow you to see an
expert in a dedicated area where you can receive sympathetic assistance away
from busy, and often fraught, accident and emergency departments.

Flowchart
showing a flowchart for the treatment management for
abortion.

At one time, we believed that if you miscarried between
seven and thirteen weeks, there were likely to be retained
products of pregnancy and an ERPC (evacuation of retained
products of conception) was indicated to reduced the risk of
infection and bleeding.

In the days before legal termination
of pregnancy (Chapter
19) infection with induced abortion was relatively
common. These septic abortions could be life threatening.
Current opinion is that the risk of infection and bleeding
has been overstated and a conservative approach now seems
safe.

From your point of view, this means that you may not
need an operation which, as always, carries an element of
risk (surgery
risks) and furthermore delays waiting for an operation
slot are avoided. A repeat scan about ten days after the
diagnosis of incomplete abortion will usually confirm that
nature has solved the problem for you and the womb has
completely emptied itself.
If a abortion is incomplete, oral misoprostol 600
micrograms may be as safe as surgical evacuation.

If you are Rhesus negative you should be offered an
injection of Anti-D to reduce the chance of rhesus problems
in a future pregnancy. Guidelines for the administration of
Anti-D are currently under review.

The emotional aspects of abortion can be difficult to
deal with particularly if you have had difficulty conceiving
or if this is not your first abortion. There is
inevitably a time of grieving. A trained counsellor with a
special interest in abortion can provide support and help
you come to terms with your loss.

Pregnancy after Abortion.

If you are pregnant after a previous
abortion, the chances are that the pregnancy
will be successful. Even after three
abortions, your chance of a successful
pregnancy is 55%.

Usually nature has detected some problem such as a chromosome abnormality (genes
- chromosomes) and decides that it is in your interests to discontinue
this pregnancy and give you an early chance to start a successful one. A
blighted ovum (Q12.4),
or an embryo with an abnormality would be reasons for spontaneous
abortion. Occasionally there may be a different and perhaps remedial
cause which would need consideration if you have three abortions.

How can we ensure that I will not miscarry
again?

It is an understandable cry from the heart from couples who experience the
devastation of recurrent pregnancy loss that there must be one explanation
and one perfect treatment. Even if a cause is identified we are unlikely to
achieve success rates better than 75% within the foreseeable future. Half of
the fifteen percent of pregnancies that miscarry can be attributed to a
genetic problem of the embryo and we do not have a remedy for this. It is
only in the last ten years that we have begun to find some treatable
explanations for recurrent abortions.

For those with identified antiphospholipid antibody
problems aspirin alone or in combination with heparin has
been shown to be beneficial. Twenty percent of women have
PCOS (Q7.2)
and this syndrome may perhaps account for a greater
proportion of recurrent abortions. Metformin looks
promising on theoretical grounds but we still lack the
scientific proof that is required. The role of bacterial
infection and the possible benefit of antibiotics is an
example of a new area that is being investigated. There is a
suggestion that 'tender loving care', with frequent
assessment during pregnancy, may help. There is no evidence
that hormone support in pregnancy or low-dose aspirin for
those without evidence of antiphospholipid antibody problems
improves the outcome.

There is some evidence that metformin treatment for PCOS
may be beneficial but more robust research is required
before it can be implemented in routine clinical care.

Support Groups

This is the personal website of David A Viniker MD FRCOG, retired Consultant Obstetrician and Gynaecologist - Specialist Interests - Reproductive Medicine including Infertility, PCOS, PMS, Menopause and HRT.I do hope that you find the answers to your women's health questions in the patient information and medical advice provided.

The aim of this web site is to provide a general
guide and it is not intended as a substitute for a consultation
with an appropriate specialist in respect of individual care and
treatment.

David Viniker retired from active clinical practice in 2012. In 1999, he setup this website - www.2womenshealth.com - to provide detailed
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